Gecko:
U+0 - U+20 creates text node
U+21 creates comment node
U+22 - U+2e creates text node
U+2f creates comment node
U+30 - U+3e creates text node
U+3f creates comment node
U+40 creates text node
U+5b - U+60 creates text node
U+7b - U+d7ff creates text node
U+e000 - U+ffff creates text node